The present invention relates to a process for producing a semiconductor component by diffusion, with prior ion implantation and also relates to a semiconductor component obtained by this process. It is used in semiconductor technology, in the production of electronic or optoelectronic devices using types III-V semiconductor compounds, such as field effect transistors, bipolar transistors, integrated circuits, detectors, lasers, light emitting diodes, etc.
Type III-V semiconductor compounds are understood to mean semiconductors in the composition of which are used elements of columns III and V of the periodic classification. The term component is understood to cover a device comprising one or more doped or undoped layers.
The semiconductors used in electronic or optoelectronic devices generally comprise layers doped with different types (p and n), which form the junctions. The depth of a junction is an important parameter, which determines the performances of the component. Two processes are generally used for producing such doped layers, namely ion implantation and thermal diffusion.
Generally preference is given to the thermal diffusion process for doping at a relatively great depth with transition metals and for doping at high concentrations. However, this process forces problems in connection with the control of the depth in the case of certain dopant/semiconductor pairs (e.g. zinc in InP). These problems are due to the fact that the diffusion coefficients can be high, even at low temperatures, or that the still inadequately understood problems of abnormal diffusion cause diffusion "tails" extending well beyond the planned depths.